The new tech developed by Hitachi Kokusai Electric achieves super-fast speeds by processing video as it’s recorded—much like the facial recognition technology used in digital cameras. That means that once the footage is recorded, finding a face in the crowd in hours and days of recordings is a simple database search. There are some limitations to the system. It can only scan faces within 30 degrees vertically or horizontally from the camera and the faces have to be at least 40 x 40 pixels in size.